The paper reports SANS (small angle neutron scattering) experiments on aqueous binary suspension mixtures of charged polystyrene latex and silica particles, characterized by the size ratio, gamma=sigma(si)/sigma(ps)similar to 0.72, with a nominal polystyrene diameter, sigma(ps)=91 nm. The scattered intensities are reported over the wave vector (Q) range 0.025 < Q/nm(-1) < 0.4. Partial scattered intensities were obtained by contrast matching the constituents with an appropriate D2O/H2O solvent. Results are presented for mixtures at a volume fraction phi(T)=0.1 as a function of the number ratio, n=N-ps/N-si; n=2/1, 1/1, 1/2, and 1/4. The partial scattered intensity of polystyrene differs significantly from that of silica at a given value of n, and the partial scattered intensity of a component in a mixture suspension can differ markedly from the equivalent scattered intensity of the component in a pure suspension. The variation of the intensity with Q for silica in a 1/1 mixture suggests long range silica order at low Q. There is some evidence that the larger component, polystyrene, may form a polycrystalline fee phase, in agreement with the density functional theory. The effect of multiple scattering on the data is discussed.